[Unity] Wrap UnityEditor in the UNITY_EDITOR directive

I suggest teaching the plug-in for Unity to automatically wrap in the directive
#if UNITY_EDITOR
#endif

Those links that lead from the runtime assembly to the assembly editor.
These include, for example, namespace UnityEditor.
In a broader sense, it's also the editor's assemblies created by the developer (located in the project's "Editor" folder, or having an editor platform only in asmdef-file)

(Ru: предлагаю научить плагин юнити автоматически оборачивать using'и в директиву UNITY_EDITOR, если он ведет из Runtime-сборки на сборку редактора)